The invention relates to communication networks with GMPLS control plane, and more precisely to the setting up of a connection between portions of a distributed application between nodes connected to such networks.
By “communication network with GMPLS control plane” is meant a label switched network of the type known as “packet switched” and having a GMPLS (for “Generalized Multi Protocol Label Switching”) architecture, such as ATM, Frame Relay (FR), IP and Ethernet networks, or of the type known as “circuit switched” having a GMPLS architecture, such as TDM (such as SONET/SDH, PDH, G.709) networks, wavelength switching networks or spatial switching networks (such as switching from an input port to an output port).
It is recalled that, in a label switched network, the connection paths which are set up between nodes (or “hosts”) are called LSPs (for “Label Switched Paths”).
Because of the trend to integration and distribution of information systems, the quantity of data which is transported by networks, be it on demand or in an organised way, is growing more rapidly than the quantity of data which can be acquired and processed by so-called centralised applications. Accordingly, networks must increasingly become collaborative media for exchanging data and have a core of high level services supported by access suppliers, while at the same time providing basic bandwidth and connectivity services.
These high level services cater for applications which use distributed resources, such as GRID, e-Science, e-Government, IPTV (for “Internet Protocol TeleVision”) or VoD (for “Video on Demand”). Such applications, called hereafter “distributed applications” because they incorporate at least two portions installed in the nodes connected to the network, require a co-operative and adaptive service(s) control plane, based on the Internet protocol (IP), such as the GMPLS control plane.
In order that application portions might operate in parallel, they must be interconnected, by means of a connection path with Quality of Service (or QoS), of the LSP type. In order to set up such a connection, the nodes in which the portions of a distributed application are installed must communicate their needs in terms of network resources. In order to do this, they use, for example, the resources reservation protocol, or RSVP, and more specifically RSVP messages of the “path message” and “Resv message” types. As these nodes are external to the network, although connected to the latter, RSVP messages are exchanged directly, without the network being able to control this exchange. However, the majority of carriers forbid the direct reservation of resources by user nodes (external their networks) as this interrupts their internal resource reservation mechanism.